One or more example embodiments of the inventive concepts relate to a non-contact type communication apparatus, a system and/or a method of operating the system. For example, at least some example embodiments relate to a card reader for communicating with a near-field communication (NFC) card, a system including the card reader, and/or a method of operating the card reader.
An NFC card reader may restore a signal component that overlaps with a magnetic field component of 13.56 MHz induced by an antenna, and may convert the restored signal to a digital signal. When the amplitude of the restored signal is low, the restored signal may not easily be converted into the digital signal, therefore, to amplify the restored signal to a level sufficient to convert the restored signal into a digital signal, the NFC card reader may amplify the restored signal before converting the restored signal.
When a distance between a card and the card reader is large, the card reader may need to use a high gain when performing signal amplification to restore a low-amplitude signal to a level sufficient to establish communication. In contrast, when the distance between the card and the card reader is small, the card reader may need to use a low gain so as to prevent a high-amplitude signal from being saturated.